Anaerobic and aerobic metabolism of glycogen-accumulating organisms selected with propionate as the sole carbon source
Contribuinte(s) |
C.J. Dorman |
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Data(s) |
01/01/2006
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Resumo |
In the microbial competition observed in enhanced biological phosphorus removal (EBPR) systems, an undesirable group of micro-organisms known as glycogen-accumulating organisms (GAOs) compete for carbon in the anaerobic period with the desired polyphosphate-accumulating organisms (PAOs). Some studies have suggested that a propionate carbon source provides PAOs with a competitive advantage over GAOs in EBPR systems; however, the metabolism of GAOs with this carbon source has not been previously investigated. In this study, GAOs were enriched in a laboratory-scale bioreactor with propionate as the sole carbon source, in an effort to better understand their biochemical processes. Based on comprehensive solid-, liquid- and gas-phase chemical analytical data from the bioreactor, a metabolic model was proposed for the metabolism of propionate by GAOs. The model adequately described the anaerobic stoichiometry observed through chemical analysis, and can be a valuable tool for further investigation of the competition between PAOs and GAOs, and for the optimization of the EBPR process. A group of Alphaproteobacteria dominated the biomass (96% of Bacteria) from this bioreactor, while post-fluorescence in situ hybridization (FISH) chemical staining confirmed that these Alphaproteobacteria produced poly-beta-hydroxyalkanoates (PHAs) anaerobically and utilized them aerobically, demonstrating that they were putative GAOs. Some of the Alphaproteobacteria were related to Defluvicoccus vanus (16% of Bacteria), but the specific identity of many could not be determined by FISH. Further investigation into the identity of other GAOs is necessary. |
Identificador | |
Idioma(s) |
eng |
Publicador |
Soc General Microbiology |
Palavras-Chave | #-anaerobic And Aerobic Metabolism #Carbon Source #Microbiology #Biological Phosphorus Removal #Activated-sludge Systems #In-situ Identification #Laboratory-scale #Microbial-populations #Acetate Uptake #Polyphosphate #Model #Stoichiometry #Competition #C1 #270399 Microbiology not elsewhere classified #779999 Other |
Tipo |
Journal Article |